A single rosemary blossom is extremely small:

Length: about ¼ inch (0.25 in)
Width: about ⅛ to ¼ inch (0.125–0.25 in)
The full cluster above spanned a grand total of about ½ inch across.

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General Information
Rosemarry flowers bloom in cool seasons—often late winter through early spring.
They’re edible, with a lighter, sweeter flavor than the leaves.
They’re excellent for pollinators, especially bees.